If $$3x + 4y - 2z + 9 = 17, 7x + 2y + 11z + 8 = 23$$ and $$5x + 9y + 6z - 4 = 18$$, then what is the value of $$x + y + z - 34$$?

A

-28

B

-14

C

-31

D

-45